It's now time to verify the effectiveness of my idea to give the door a real "studded" look.

While I was searching for something useful inside every drawer (not only mine), I happened to find a box of common head pins. I immediatly realized that those pins could do the trick. Size and shape were perfect, only the color didn't suit: I needed something darker, more similar to the iron parts of my door, these shiny pins would had been a wrong note. I had to make them darker in some way.
The use of a marker was discarded (not long-lasting and of uncertain effect with light reflections), so I thought... "Maybe I can burn them!".
So here we are. Will it work? Let's make a test...

Yes! Here are the first studs just burnt:

I make another simple test on a discarded plank to be sure about the final effect. Nailing a cut head into the plank I can see that the wood doesn't split and it looks convincing enough. Now I can go on with the real work.
I just need the heads, so there aren't enough pins to finish both shutters. I must buy a new box and the new pins seem harder to darken with fire, but the difference is barely visible.

I start placing the studs along three vertical lines, then flanked by two more inner lines on part of the planking. Possibly I'll put more pins to cover all the surface, but I'll try not to overload the door.
In the meantime, on the outside face of the small door I place a ring as a knocker (another pin has been placed under the ring after taking these pictures).

The main door is now ready to be mounted on its hinges. To be precise, it would be ready if the hinges would had been placed into the wall, but that's not it.
I must thicken the wall a few millimeters on the inside for the hinges to fit. The space I planned there is not enough and the hinges need to be well inserted into the stones to be stronger.

After this operation I can finally test the functionality of the door and both shutters fit perfectly.
As the walls keep growing I'll place the middle and upper hinges, definitively fasten the door in its position. From that moment on it will be impossible to anyone not expressly invited to get inside the Domus.

Don't worry, if you introduce yourself as a friend of mine, no door will cut your path!